Marcoux S, Brisson J, Fabia J
Department of Social and Preventive Medicine, Laval University, Sainte-Foy, Quebec, Canada.
Am J Epidemiol. 1989 Nov;130(5):950-7. doi: 10.1093/oxfordjournals.aje.a115427.
This case-control study assessed the relation of cigarette smoking during pregnancy to the risk of preeclampsia and gestational hypertension. All subjects were primiparous women without a history of high blood pressure who gave birth in Quebec City or Montreal, Canada, hospitals between 1984 and 1986. Cases (172 women with preeclampsia and 251 with gestational hypertension) and 505 controls were interviewed at the hospital after delivery. Adjusted relative risks were estimated by polychotomous logistic regression. Compared with women who had never smoked, women who were smokers at the onset of pregnancy had a reduced risk of preeclampsia (relative risk = 0.51, 95% confidence interval 0.34-0.77). Relative risks of preeclampsia decreased with increases in the number of cigarettes smoked daily at the onset of pregnancy: Relative risks among smokers of less than 11, 11-20, and more than 20 cigarettes per day were 0.79, 0.56, and 0.38, respectively (test for trend: p = 0.0002). The protective effect of smoking on preeclampsia was stronger for women who continued to smoke after 20 weeks of pregnancy. While smoking tended to reduce the risk of gestational hypertension, this effect was less evident than that for preeclampsia. Relative risks varied little with severity of disease as based on gestational age at the onset of hypertension, maximal blood pressure and, for preeclampsia, amount of proteinuria. The reduction in mean birth weight attributable to smoking during pregnancy was similar among cases and controls. Nicotine inhibition of thromboxane A2 production might explain the decreased risk of pregnancy-induced hypertension among smokers. Despite these findings, the harmful consequences of smoking on pregnancy outcome outweigh its protective effect against pregnancy-induced hypertension.
这项病例对照研究评估了孕期吸烟与先兆子痫和妊娠期高血压风险之间的关系。所有研究对象均为初产妇，无高血压病史，于1984年至1986年间在加拿大魁北克市或蒙特利尔市的医院分娩。病例组（172例先兆子痫妇女和251例妊娠期高血压妇女）和505例对照组在产后于医院接受访谈。通过多分类逻辑回归估计调整后的相对风险。与从不吸烟的女性相比，妊娠开始时吸烟的女性患先兆子痫的风险降低（相对风险=0.51，95%置信区间0.34 - 0.77）。妊娠开始时先兆子痫的相对风险随着每日吸烟量的增加而降低：每日吸烟量少于11支、11 - 20支和超过20支的吸烟者的相对风险分别为0.79、0.56和0.38（趋势检验：p = 0.0002）。吸烟对先兆子痫的保护作用在妊娠20周后继续吸烟的女性中更强。虽然吸烟倾向于降低妊娠期高血压的风险，但这种作用不如对先兆子痫那么明显。根据高血压开始时的孕周、最高血压以及先兆子痫时的蛋白尿含量，相对风险随疾病严重程度变化不大。孕期吸烟导致的平均出生体重下降在病例组和对照组中相似。尼古丁对血栓素A2生成的抑制作用可能解释了吸烟者妊娠诱导性高血压风险降低的原因。尽管有这些发现，但吸烟对妊娠结局的有害后果超过了其对妊娠诱导性高血压的保护作用。
